Arctic Blast Grips Canada as US Records Most Unseasonably Mild Christmas on Record.
A prolonged deep freeze has enveloped an intense and prolonged cold spell, with temperatures hovering from 20 to 40 degrees below zero for multiple weeks. A reading of -55.7 Celsius was logged in Braeburn, Yukon, on Tuesday, marking its chilliest December reading since 1975.
Enduring Chill of Extreme Cold
Similarly, the communities of Mayo and Dawson experienced sixteen nights in a row dipping under the minus 40 Celsius threshold, with Mayo experiencing a low of -50.4C at the start of the week. The capital, Whitehorse, likewise saw 10 nights when readings fell to minus 30 degrees or lower.
The deep freeze spread farther south through Christmas week. Christmas night saw Edmonton's temperatures plummet below minus 28C.
Boxing Day was expected to bring minimum temperatures of at least minus 20C across many regions, from Edmonton in the west to Quebec in the east.
Likely to Linger For Days to Come
The frigid conditions are predicted to linger for the foreseeable future. Officials have warned that the Yukon could face electricity outages over the next several days, as the system endures record-high pressure from historically high electricity consumption.
The prolonged chill has been caused by the Arctic vortex settling above Canadian territory through December, enabling a surge of icy Arctic winds to descend. Next week, the cold air mass is expected to retreat north gradually, enabling milder Pacific air to move across America and reach into portions of southern Canada.
Dramatic Difference Compared to Stateside Temperatures
Meanwhile, in a dramatic contrast, areas of the United States saw the hottest December 25th in their history as temperatures soared about 15-30C above the seasonal average. In many areas, conditions felt more typical of April or May instead of the heart of winter.
Several states set Christmas Day temperature records. Oklahoma City, Oklahoma, reached 25 degrees Celsius on Christmas, surpassing the previous peak of 22C set in 1982. Metropolitan areas such as Austin, Dallas, and Charlotte were also among those that recorded temperatures above 25C.
Atmospheric Ridge Sustains High Temperatures
Unseasonable heat is predicted to persist through Boxing Day and the days ahead, with abnormal warmth projected to move across the southeastern US in the coming days.
This heat is being driven by a strong upper-level ridge reaching from the arid southwest across the continent, establishing a classic heat-dome pattern. This pattern establishes a broad area of high pressure across much of the continent, trapping warm air near the surface. Sinking atmospheric air undergoes compression and additional heating, enabling abnormally high temperatures to develop.
